Battery needed for Barn Burner

Closed to comply with forum rules.


Hello all,

Has anyone had to replace their battery pack for their Barn Burner recently?
I am unable to locate any cells for the pack (ICR18650-22E, SAMSUNG SDI). My
BB is at XeVision awaiting replacement of a circuit board, but my battery pack
is also bad and XeVision does not have any batteries and can't get anymore.
They suggested purchasing a battery from batteryjunction. I called
Battery Junction but they do not have any spare battery packs for their
Titanium Innovations L70 (Barn Burner clone). I had XeVision send me the bad
battery pack so that I can build my own pack or try to find someone to rebuild
it for me.

If someone out there has already built a replacement pack for their BB, please
let me know how you went about it; specifically, what batteries did you use,
where did you purchase them, shrink wrap used, etc. Any help would be greatly
appreciated. If anyone has a GOOD spare BB battery pack for sale, please send
me a PM with details. Thanks.

Edward

For a 75W light and a runtime of >h hours you'd need >75 w-h of battery capacity at your particular discharge current.

The guy up the street wanted to replace the batteries in his electric scooter but your problem is easier since scooter power draw depends on a lot of factors. A constraint on his choice based on what I knew at the time about batteries [and his budget] was that we pretty well had to stick to deep cycle SLA.

There are a couple places online that sell cells of all types and fabricate packs as a routine. ICR18650 is a typical Lithium Ion, probably a 2200 mAh capacity cell. I'd call CheapBatteryPacks.com and ask them about making up a pack for you using at least 18650, 2600 or even 2900 mAh cells. They can make them in any configuration. You could probably send them the old pack and they can copy it. I'm not completely sure, but I think all the circuitry/intelligence for the light is on the board, not wrapped in the pack itself. The circuitry won't care whether the capacity of the cells is less, more or the same. It is really a very simple task.

As a barnburner owner, I am interested in what u come up with.

There is a circuit board in the pack, it also must be retained.

Still great to have your participation here on the board, Dan! Thank you!

Dan, is it a typical over dis-charge, over-charge and current limiting board? If so, then they would want to get unprotected cells so there are not conflicting set points between cell protection boards and your board?

Not sure CBP does this work. BatterySpace.com does.

ww.epectec.com/batteries/quote/battery_rfq.asp

If that battery pack PCB were bad we have some spare old (bad) packs, good PCB on board. The circuit board (PCB) can be stolen from 1 of those if necessary. We would provide that at no charge.

BVH said:

Dan, is it a typical over dis-charge, over-charge and current limiting board? If so, then they would want to get unprotected cells so there are not conflicting set points between cell protection boards and your board?

Not sure CBP does this work. BatterySpace.com does.

ww.epectec.com/batteries/quote/battery_rfq.asp

Click to expand...

The board does control charging to the banks of cells. I would use the P/N of the cells he provided, at the beginning of this thread. That is what was used. I provided that information to him.

Thanks everyone for your input/suggestions. I found some replacement 18650 cells that look like they would work:

http://www.batteriesinaflash.com/as...cylindrical-rechargeable-battery-3-7v-2800mah
http://www.batteryspace.com/ultra-h...lindrical-rechargeable-cell-3.7v-2800mah.aspx

Hopefully either CheapBatteryPacks or Batteryspace can build me a pack. I will let you know once I find out something.

Elnino, if it is helpful I had taken these photos in a thread from 2007. I know you can remake these packs with original circuit board, and use a larger red shrink wrap. I used cells I got from a power tool pack that was < $40, but would have to go back and look up all that. If you ask BatterySpace to do it, make sure they know the wiring config must be exact. I believe that Dan's price on a replacement pack was around $200, so you can use that as a guide. I think the original Samsung cells were 2200mAh. Maybe Dan has some alternatives, as Li-Ion cells deteriorate over years and/or amount used/cycled, even under ideal maintenance/storage conditions.

This quoted post was back in the days when I was not knowledgeable about how groups of cells in parallel got balanced with the other cells in the pack. The circuitboard does that very well, comparing each of the 4 groups of 3 cells in parallel to each other and adjusting voltage to keep all cells balanced.

I have an extra battery pack from my BarnBurner that I carefully peeled off layers to confirm that these are using 4S-3P of 12 Samsung Unprotected 18650 cells. As far as I know, this pack has never been used, and I charged it one time about 2 months ago.

The pack voltage gives 16.55V and fortunately each of the cells gives a reading between 4.13 - 4.15V, but again an imbalance would only develop over repeated discharge and charging. There are no individual cell taps for balancing this pack.

Click on each thumbnail image for larger view.

Click to expand...

This was the rebuilt one with new cells:

LuxLuthor, the info/pictures in your post is very informative and I'm sure will be helpful in getting my replacement
pack built. Thank you! I will be providing it to both CheapBatteryPacks and BatterySpace with the hope that one of
them will make one for me.

Today I received emails from both Batteryspace and Cheapbatterypacks and here are their replies:


Batteryspace.com:

Base on the info you provide, we can use 12 pcs of this 18650 2.6Ah cell (part no: Part Number: LC-18650-LG-2600) to rebuild you a 14.8V 7.8Ah pack. If you send your pack to us and we can rebuild it for $175.00.

I don't recommend the 2800mAh or higher cell as to reach that capacity, you will need a charger that is capable to charger each cell upto a max of 4.3V while most Li-Ion charger can only charge each cell to a max of 4.2V. Therefore, you won't get the rated capacity of the cell. Beside, you increase the capacity from original 6.6Ah to 7.8Ah.

Please note: we will use your original pcb and connectors to rebuild it. Also, we are not liable if the pack is not working properly due to problem with the pcb you have. We have our own pcb but I don't know what is the max current being draw by your light to see what will suit you best.


Cheapbatterypacks.com:

We could build it using the A123 cells. Slightly lower voltage at 3.3v per cell but the A123 have higher average discharge capabilities over LION so the end result should be higher watts.

The cells are 1100mah from A123 (A grade cells not clones or low grade).

For 12 cells you are looking at 18.00 per cells = $216.00 per pack (4s3p) = 3300mah, 13.2v

Lion can be found overseas for a lot less money but I am not sure on quality. We have tested a few that do not do well at high discharge rates.

**********************************


I am leaning towards the pack with the 18650 cells and though not recommended, to go with the 2800mah cells vs. the 2600mah.
The only way that I have ever charged the pack is using the wall charger that came with the light. Does anyone know if that
charger can charge the 2800mah cells to a max of 4.3v as stated above? Any suggestions on which would be the better pack for
my BB would be appreciated. Thanks in advance.

I would not use the A123 for sure. The question is not if the charger can reach that voltage, but rather what is the setup of the PCB which is controlling the charge current and voltage cutoff. I don't know if there is a separate board inside the light that controls the charge current/voltage process in addition to the one in the pack. If you cannot verify the PCB limits, I would use 4.2V cells.

That is actually a pretty good deal for battery space to rebuild it less than Dan was selling them for, and is cheaper than I expected it would be. I would STRONGLY recommend that you remove the shrink wrap and take detailed photos of all the sides before sending so you verify they did everything right before installing it in your light....which means you would need some shrink wrap.

Decision Theory says, "Other things being equal go for the fewest $/mAh."

Agree with Lux. No A123's for sure. No 4.3V cells. The electronics in the BB were designed for 4.2 Volt cells. As mentioned, you've already gained mAh capacity by going to the 2600 mAh cells so you have more run time btw charges without having to experiment with the 4.3 Volt cells.

xul said:

Decision Theory says, "Other things being equal go for the fewest $/mAh."

Click to expand...

Generally a sensible idea, as long as you don't go as low as the ***Fire crappy Chinese made Li-Ion cells. In this instance however, there is significant labor involved in building the custom pack, so I would start with higher quality cells like LG or Samsung that will last and perform.

Thank you LuxLuthor and BVH. I will go with the 18650 2600mAh cells.

For 0.2A to 5A, depending on the brand and current draw you can expect between 2900 and 1800 mAh actual capacity.

I was rereading the email that Batteryspace sent me:

"...I don't recommend the 2800mAh or higher cell as to reach that capacity, you will need a charger that is capable to charger each cell up to a max of 4.3V while most Li-Ion charger can only charge each cell to a max of 4.2V. Therefore, you won't get the rated capacity of the cell. Beside, you increase the capacity from original 6.6Ah to 7.8Ah..."

Okay, so I won't get the rated capacity of the cells, but what I would get is up to 3 times the charge/recharge cycles using the 2800mah cells vs. 2200/2600mah cells. Here is a thread where Silverfox mentions that by charging to 4.1 instead of 4.2 you can gain up to 1500 charge/discharge cycles:

SilverFox said:

charging to 4.2 volts gave around 400 - 500 charge/discharge cycles where charging to 4.1 volts gave around 1500 charge/discharge cycles. The down side is a loss of around 10% of the cells capacity.

Tom

Click to expand...

Would the same apply if I only charge to 4.2 instead of 4.3? I wouldn't mind losing 10% cell capacity if I am able to triple my charge/discharge cycles.


The options are:

2200mah cells = 6.6ah
2600mah cells = 7.8ah
2800mah cells at 90% = 7.5ah
2800mah cells at 87% = 7.3ah


AW's Li-ion battery thread over at CPF Marketplace shows:

LiIon Battery Charge Status

4.2V – 100%
4.1V – 87%
4.0V – 75%
3.9V – 55%
3.8V – 30%
3.5V – 0%



Since the BB charging system is most likely programmed for 4.2v charging - would using the 2800mah cells (4.3v needed for max/rated capacity as stated by Batteryspace) gain additional charge/discharge cycles, 1200 - 1500 instead of 400 -500 by only charging to 4.2v? Either figure (7.5ah or 7.3ah) for the 2800mah cells sounds good to me considering all the charge/discharge cycles I'd gain. Will this work or not? Thanks.